Commit 5cbd9602 authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

mlxsw: spectrum_qdisc: Allocate child qdiscs dynamically 



Instead of keeping qdiscs in globally-preallocated arrays, introduce a
per-qdisc-kind value num_classes, and then allocate the necessary child
qdiscs (if any) based on that value. Since now dynamic allocation is
involved, mlxsw_sp_qdisc_replace() gets messy enough that it is worth it to
split it to two cases: a new qdisc allocation and a change of existing
qdisc. (Note that the change also includes what TC formally calls replace,
if the qdisc kind is the same.)

Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cff99e20

drivers/net/ethernet/mellanox/mlxsw/spectrum_qdisc.c

+83 −32
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ struct mlxsw_sp_qdisc_ops { 
			  struct mlxsw_sp_qdisc *mlxsw_sp_qdisc, void *params);

	struct mlxsw_sp_qdisc *(*find_class)(struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,

					     u32 parent);

	unsigned int num_classes;

};



struct mlxsw_sp_qdisc {
@@ -74,7 +75,6 @@ struct mlxsw_sp_qdisc { 


struct mlxsw_sp_qdisc_state {

	struct mlxsw_sp_qdisc root_qdisc;

	struct mlxsw_sp_qdisc tclass_qdiscs[IEEE_8021QAZ_MAX_TCS];



	/* When a PRIO or ETS are added, the invisible FIFOs in their bands are

	 * created first. When notifications for these FIFOs arrive, it is not
@@ -215,29 +215,41 @@ mlxsw_sp_qdisc_destroy(struct mlxsw_sp_port *mlxsw_sp_port, 
	if (mlxsw_sp_qdisc->ops->destroy)

		err = mlxsw_sp_qdisc->ops->destroy(mlxsw_sp_port,

						   mlxsw_sp_qdisc);

	if (mlxsw_sp_qdisc->ops->clean_stats)

		mlxsw_sp_qdisc->ops->clean_stats(mlxsw_sp_port, mlxsw_sp_qdisc);



	mlxsw_sp_qdisc->handle = TC_H_UNSPEC;

	mlxsw_sp_qdisc->ops = NULL;



	mlxsw_sp_qdisc->num_classes = 0;

	kfree(mlxsw_sp_qdisc->qdiscs);

	mlxsw_sp_qdisc->qdiscs = NULL;

	return err_hdroom ?: err;

}



static int

mlxsw_sp_qdisc_replace(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle,

static int mlxsw_sp_qdisc_create(struct mlxsw_sp_port *mlxsw_sp_port,

				 u32 handle,

				 struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,

				 struct mlxsw_sp_qdisc_ops *ops, void *params)

{

	struct mlxsw_sp_qdisc *root_qdisc = &mlxsw_sp_port->qdisc->root_qdisc;

	struct mlxsw_sp_hdroom orig_hdroom;

	unsigned int i;

	int err;



	if (mlxsw_sp_qdisc->ops && mlxsw_sp_qdisc->ops->type != ops->type)

		/* In case this location contained a different qdisc of the

		 * same type we can override the old qdisc configuration.

		 * Otherwise, we need to remove the old qdisc before setting the

		 * new one.

		 */

		mlxsw_sp_qdisc_destroy(mlxsw_sp_port, mlxsw_sp_qdisc);

	err = ops->check_params(mlxsw_sp_port, params);

	if (err)

		return err;



	if (ops->num_classes) {

		mlxsw_sp_qdisc->qdiscs = kcalloc(ops->num_classes,

						 sizeof(*mlxsw_sp_qdisc->qdiscs),

						 GFP_KERNEL);

		if (!mlxsw_sp_qdisc->qdiscs)

			return -ENOMEM;



		for (i = 0; i < ops->num_classes; i++)

			mlxsw_sp_qdisc->qdiscs[i].parent = mlxsw_sp_qdisc;

	}



	orig_hdroom = *mlxsw_sp_port->hdroom;

	if (root_qdisc == mlxsw_sp_qdisc) {
@@ -253,20 +265,46 @@ mlxsw_sp_qdisc_replace(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle, 
			goto err_hdroom_configure;

	}



	mlxsw_sp_qdisc->num_classes = ops->num_classes;

	mlxsw_sp_qdisc->ops = ops;

	mlxsw_sp_qdisc->handle = handle;

	err = ops->replace(mlxsw_sp_port, handle, mlxsw_sp_qdisc, params);

	if (err)

		goto err_replace;



	return 0;



err_replace:

	mlxsw_sp_qdisc->handle = TC_H_UNSPEC;

	mlxsw_sp_qdisc->ops = NULL;

	mlxsw_sp_qdisc->num_classes = 0;

	mlxsw_sp_hdroom_configure(mlxsw_sp_port, &orig_hdroom);

err_hdroom_configure:

	kfree(mlxsw_sp_qdisc->qdiscs);

	mlxsw_sp_qdisc->qdiscs = NULL;

	return err;

}



static int

mlxsw_sp_qdisc_change(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle,

		      struct mlxsw_sp_qdisc *mlxsw_sp_qdisc, void *params)

{

	struct mlxsw_sp_qdisc_ops *ops = mlxsw_sp_qdisc->ops;

	int err;



	err = ops->check_params(mlxsw_sp_port, params);

	if (err)

		goto err_bad_param;

		goto unoffload;



	err = ops->replace(mlxsw_sp_port, handle, mlxsw_sp_qdisc, params);

	if (err)

		goto err_config;

		goto unoffload;



	/* Check if the Qdisc changed. That includes a situation where an

	 * invisible Qdisc replaces another one, or is being added for the

	 * first time.

	 */

	if (mlxsw_sp_qdisc->handle != handle || handle == TC_H_UNSPEC) {

		mlxsw_sp_qdisc->ops = ops;

	if (mlxsw_sp_qdisc->handle != handle) {

		if (ops->clean_stats)

			ops->clean_stats(mlxsw_sp_port, mlxsw_sp_qdisc);

	}
@@ -274,17 +312,35 @@ mlxsw_sp_qdisc_replace(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle, 
	mlxsw_sp_qdisc->handle = handle;

	return 0;



err_bad_param:

err_config:

	mlxsw_sp_hdroom_configure(mlxsw_sp_port, &orig_hdroom);

err_hdroom_configure:

	if (mlxsw_sp_qdisc->handle == handle && ops->unoffload)

unoffload:

	if (ops->unoffload)

		ops->unoffload(mlxsw_sp_port, mlxsw_sp_qdisc, params);



	mlxsw_sp_qdisc_destroy(mlxsw_sp_port, mlxsw_sp_qdisc);

	return err;

}



static int

mlxsw_sp_qdisc_replace(struct mlxsw_sp_port *mlxsw_sp_port, u32 handle,

		       struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,

		       struct mlxsw_sp_qdisc_ops *ops, void *params)

{

	if (mlxsw_sp_qdisc->ops && mlxsw_sp_qdisc->ops->type != ops->type)

		/* In case this location contained a different qdisc of the

		 * same type we can override the old qdisc configuration.

		 * Otherwise, we need to remove the old qdisc before setting the

		 * new one.

		 */

		mlxsw_sp_qdisc_destroy(mlxsw_sp_port, mlxsw_sp_qdisc);



	if (!mlxsw_sp_qdisc->ops)

		return mlxsw_sp_qdisc_create(mlxsw_sp_port, handle,

					     mlxsw_sp_qdisc, ops, params);

	else

		return mlxsw_sp_qdisc_change(mlxsw_sp_port, handle,

					     mlxsw_sp_qdisc, params);

}



static int

mlxsw_sp_qdisc_get_stats(struct mlxsw_sp_port *mlxsw_sp_port,

			 struct mlxsw_sp_qdisc *mlxsw_sp_qdisc,
@@ -1049,6 +1105,9 @@ __mlxsw_sp_qdisc_ets_replace(struct mlxsw_sp_port *mlxsw_sp_port, 
					return err;

			}

		}



		child_qdisc->tclass_num = tclass;



		if (old_priomap != child_qdisc->prio_bitmap &&

		    child_qdisc->ops && child_qdisc->ops->clean_stats) {

			backlog = child_qdisc->stats_base.backlog;
@@ -1189,6 +1248,7 @@ static struct mlxsw_sp_qdisc_ops mlxsw_sp_qdisc_ops_prio = { 
	.get_stats = mlxsw_sp_qdisc_get_prio_stats,

	.clean_stats = mlxsw_sp_setup_tc_qdisc_prio_clean_stats,

	.find_class = mlxsw_sp_qdisc_prio_find_class,

	.num_classes = IEEE_8021QAZ_MAX_TCS,

};



static int
@@ -1239,6 +1299,7 @@ static struct mlxsw_sp_qdisc_ops mlxsw_sp_qdisc_ops_ets = { 
	.get_stats = mlxsw_sp_qdisc_get_prio_stats,

	.clean_stats = mlxsw_sp_setup_tc_qdisc_prio_clean_stats,

	.find_class = mlxsw_sp_qdisc_prio_find_class,

	.num_classes = IEEE_8021QAZ_MAX_TCS,

};



/* Linux allows linking of Qdiscs to arbitrary classes (so long as the resulting
@@ -1926,7 +1987,6 @@ int mlxsw_sp_setup_tc_block_qevent_early_drop(struct mlxsw_sp_port *mlxsw_sp_por 
int mlxsw_sp_tc_qdisc_init(struct mlxsw_sp_port *mlxsw_sp_port)

{

	struct mlxsw_sp_qdisc_state *qdisc_state;

	int i;



	qdisc_state = kzalloc(sizeof(*qdisc_state), GFP_KERNEL);

	if (!qdisc_state)
@@ -1935,15 +1995,6 @@ int mlxsw_sp_tc_qdisc_init(struct mlxsw_sp_port *mlxsw_sp_port) 
	mutex_init(&qdisc_state->lock);

	qdisc_state->root_qdisc.prio_bitmap = 0xff;

	qdisc_state->root_qdisc.tclass_num = MLXSW_SP_PORT_DEFAULT_TCLASS;

	qdisc_state->root_qdisc.qdiscs = qdisc_state->tclass_qdiscs;

	qdisc_state->root_qdisc.num_classes = IEEE_8021QAZ_MAX_TCS;

	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {

		int tclass_num = MLXSW_SP_PRIO_BAND_TO_TCLASS(i);



		qdisc_state->tclass_qdiscs[i].tclass_num = tclass_num;

		qdisc_state->tclass_qdiscs[i].parent = &qdisc_state->root_qdisc;

	}



	mlxsw_sp_port->qdisc = qdisc_state;

	return 0;

}